I would caution you about getting charge keys for others in your party. While it's technically correct that the keys can be used to decode who spent what, it's a big of a hassle. First, I've found that many come in and lay the keys down, no way to know who got which key later unless you're marked them yourself. Personally, I'd just get charging for myself and let them pay theirs with their CC directly. Now if you had separate rooms, you can get separate charging privileges.